Do a check which issue tracker is used inside the project.

app/helpers/issues_helper.rb

@@ -16,7 +16,7 @@ module IssuesHelper
   def url_for_project_issues(project = @project)
     return '' if project.nil?
 
-    if project.used_default_issues_tracker? || !project.external_issues_tracker_enabled?
+    if project.using_issue_tracker?
       project_issues_path(project)
     else
       url = Gitlab.config.issues_tracker[project.issues_tracker]['project_url']
@@ -28,7 +28,7 @@ module IssuesHelper
   def url_for_new_issue(project = @project)
     return '' if project.nil?
 
-    if project.used_default_issues_tracker? || !project.external_issues_tracker_enabled?
+    if project.using_issue_tracker?
       url = new_project_issue_path project_id: project
     else
       issues_tracker = Gitlab.config.issues_tracker[project.issues_tracker]
@@ -41,7 +41,7 @@ module IssuesHelper
   def url_for_issue(issue_iid, project = @project)
     return '' if project.nil?
 
-    if project.used_default_issues_tracker? || !project.external_issues_tracker_enabled?
+    if project.using_issue_tracker?
       url = project_issue_url project_id: project, id: issue_iid
     else
       url = Gitlab.config.issues_tracker[project.issues_tracker]['issues_url']
@@ -54,7 +54,7 @@ module IssuesHelper
   def title_for_issue(issue_iid, project = @project)
     return '' if project.nil?
 
-    if project.used_default_issues_tracker?
+    if project.default_issues_tracker?
       issue = project.issues.where(iid: issue_iid).first
       return issue.title if issue
     end

app/models/project.rb

@@ -298,14 +298,14 @@ class Project < ActiveRecord::Base
   end
 
   def issue_exists?(issue_id)
-    if used_default_issues_tracker?
+    if default_issues_tracker?
       self.issues.where(iid: issue_id).first.present?
     else
       true
     end
   end
 
-  def used_default_issues_tracker?
+  def default_issues_tracker?
     self.issues_tracker == Project.issues_tracker.default_value
   end
 
@@ -321,8 +321,12 @@ class Project < ActiveRecord::Base
     @external_issues_tracker ||= external_issues_trackers.select(&:activated?).first
   end
 
+  def using_issue_tracker?
+    default_issues_tracker? || !external_issues_tracker_enabled?
+  end
+
   def can_have_issues_tracker_id?
-    self.issues_enabled && !self.used_default_issues_tracker?
+    self.issues_enabled && !self.default_issues_tracker?
   end
 
   def build_missing_services

app/views/layouts/nav/_project.html.haml

@@ -39,7 +39,7 @@
         %i.fa.fa-exclamation-circle
         %span
           Issues
-          - if @project.used_default_issues_tracker?
+          - if @project.default_issues_tracker?
             %span.count.issue_counter= @project.issues.opened.count
 
   - if project_nav_tab? :merge_requests

lib/gitlab/markdown.rb

@@ -208,7 +208,7 @@ module Gitlab
     end
 
     def reference_issue(identifier, project = @project, prefix_text = nil)
-      if project.used_default_issues_tracker? || !project.external_issues_tracker_enabled?
+      if project.using_issue_tracker?
         if project.issue_exists? identifier
           url = url_for_issue(identifier, project)
           title = title_for_issue(identifier, project)

spec/models/project_spec.rb

@@ -195,16 +195,16 @@ describe Project do
     end
   end
 
-  describe :used_default_issues_tracker? do
+  describe :default_issues_tracker? do
     let(:project) { create(:project) }
     let(:ext_project) { create(:redmine_project) }
 
     it "should be true if used internal tracker" do
-      project.used_default_issues_tracker?.should be_true
+      project.default_issues_tracker?.should be_true
     end
 
     it "should be false if used other tracker" do
-      ext_project.used_default_issues_tracker?.should be_false
+      ext_project.default_issues_tracker?.should be_false
     end
   end